Electro-magnetically-pro felled vehicle



(No Model.) 6 SheetsSheet 1.

W. L. STEVENS.

BLEOTRO MAGNBTIGALLY PROPELLED VEHICLE.

No. 394,735. Patented Dec. 18, 1888.

n. PETERS. Photo-When Washington. n.c.

(No Model.) 6 Sheets-Sheet 2'.

W. L. STEVENS. ELEOTRO MAGNBTIGALLY PROPELLED VEHICLE. No. 394,735.Patented Dec. 18, 1888.

3 m e h S q t e e h S l 6 S N E V E T S L W (No Model.)

ELEGTRO MAGNETIGALLY PROPELLED VEHICLE. No. 394,735. Patented Dec. 18,1888.

IIIIIIIII HHHlnllll ll L (No Model.) 6 Sheets-Sheet 4.

W. L. STEVENS.

ELEGTRO MAG'NETIOALLY PROPBLLED VEHICLE.

No. 394,786. Patented Dec. 18, 1888.

'WITNEEIEIE E1- $11M: Q. 7'MM PL PETERS nib-WI, WM n, D.C.

(No Model.) 6 Sheets-Sheet 5.

W. L. STEVENS. ELBGTRO MAGNETIOALLY PROPBLLED VEHICLE. No 394,735.

nH mhL Patented Dec. 18, 1888.

L WITNEIEEEE.

(N0 Model.) 6 Sheets-Sheet 6.

W. L. STEVENS. ELEGTRO MAGNBTIGALLY PROPELLED VEHICLE. No. 394,735.Patented Dec. 18, 1888.

WITNEEEEE- INVENTUF YMQMEW n. vPains. mlo-Lmucgnpher, wins-1 m n. c

UNITED STATES \VIIILIAM. II. STEVENS, OF

PATENT GTEICE.

BOSTON, MASSACHI SE'ITS.

ELECTRO=MAGNETICALLY PROPELLED VEHICLE.

SPECIFICATION forming part of Letters Patent No. 394,735, dated DecembBr 18, 1888. Application filed April 19, 1888. Serial No. 271,138. (Nomodel.)

To (all 112710720 it may concern.-

Be it known that I, \VILLIAM L. s'IEvENs,

a citizen of the United States, residing at Boston, in the county ofSuffolk and State of Massachusetts, have in veni ed certain new anduseful ImproveIm-mts in Electro-Magnet ically-Propelled Vehicles, ofwhich the following is a specification, reference being had to thedrawings accompanying and forming a I part of the same.

This invention pertains generally to electro-magneticallypropelledvehicles, and more particularly to those which carry the electricalgenerator or batteries which produce or afford the current for operatingthe motor.

In describing my invention I shall refer exclusively To street-carswhich carry a battery of secondary or storage cells, which at intervalsrequire to be charged from a generator. I would not, however, beunderstood as limiting myself to this particular system, for in. lieu ofstorage-batteries I may use primary or voltaic batteries, and as to theapparatus which I shall herein describe it will be apparent to oneskilled in the art that in many respects it may be used for or adaptedto such cars as receive the current from a stationary generator in anyof the ways now known.

In my present invention my aim has been to secure a street-car capableof being propelled economically, safely, and wi iii an easilycontrolledpower that insures a reasonable speed on all the ordinary levels,grades, and curves of a municipal or suburban track, and theseconditions I have realized by apparatus the capabilities of which arelimited only by the size of the motors and number of batterycells whichit is found practicable to carry. \Vithout reference, then, to thevarious applications ot' the apparatus which forms the invention, nor tothe purely mechanical devices-such as speed-reducing and running gearsIshall describe the devices for starting, stopping, reversing,regulating, and controlling the motor through the agency of elec tricalenergy. These devices I have classified according to their specialfunctions, and in order to avoid complication I shall describe eachindependently as far as practicable, pointing out in the claims thosefeatures which I regard as the novel and the essential parts of myinvention.

1 Referring to the accompanying drawings,

Figure 1 is a view, partly in section and partly in side elevation. of astreet-car equipped with apparatus construct ed in accordance with myinvention. Fig. is a horizontal section through a car, a portion of thebottom being removed to exhibit the motor and motiontransmittingdevices, under the car-body. Fig. 3 is a plan view of the main orcurrent-controlling switch mechanism. .l ig. i is an end view of thesame. Fig. 5 is an end view of the speed-controlling switch. Fig. 6 is aplan view of the same. Fig. 7 is a vertical central section of mechanismfor operating the switches. Fig. 8 is a section on linear of Fig. T.Fig. S) is a diagram illustrating the electrical connections between thebatteries, switches, and motor. Fig. 10 is a diagram illustrating morein detail the connections and mode of operation of the main orcurrentcontrolling switch. Figs. 11, 12, i3, and II are diagramsillustrating the order or condition of the connections of the mainswitch for different positions of the brushes or contacts of the mainswitch. Fig. 15 is a diagram il lustrating in another way the plan ofconnections between the main and two speed switches.

Let A represent any suitable vehiclesuch as a street-car by which asuitable number of primary or secondary battery-cells, B, is carried. Iprefer to place the batteries under the seats of the car, as indicated.

Fnder the car-body is secured in any proper manner an electroanagneticmotor, A, connected by a belt, A, or otherwise, with the drivers (I,either directly or through suitable reducing-gears.

The con'imutator of the motor is provided with four brushes, b 1) Z1 Z1,mounted on a tilting frame, 0, which is adapted to be shifted by a rod,(1, supported under the car, and which is shifted from either end of thecar. This is an ordinary form of mechanism for reversing the directionof a motor, and any other may be substituted for it.

I place under the floor of the car 1 he switches for controlling themovements of the motor. These consist, essentially, of a main orcurrent-controlling switch and what I term a speed-switch, the functionsof which will i be hereinafter more fully described. In practice I mayuse two main and two speed switches, in order to reduce the wear uponthe switches which takes place when using one switch for running in bothdirections. In the drawings, however, and mainly with a view to avoidingcomplication, I have shown one main switch, but two speed-switches.Assuming that these switches, like most ordinary current or circuitcontrollers, contain a stationary part with terminals and a movable partwith other terminals that are to be brought into certain relations witheach other, I employ for impartin thereto th e necessary movements thedevices shown in Figs. 2, 7, and 8.

In Fig. 2, 0 represents the main switch, and C the speed-switches. IVhenonemain switch is used, the movable part or element is shifted from oneplatform by a craulearm, c, and connecting-rod (I, and from the other bya rod, B, connecting-rod (I, and crank-arm c. The

speed-switches are shifted or controlled by.

connecting-rods e and crank-arms i.

In Figs. 7 and 8 the apparatus which I use for operating the crank-armsindependently is shown. In each platform G is a metal bushing,j, held inposition by screws k,which serve, also, to support the ring j and thewasher j and to secure them to the under side of the platform. The ring7" is slotted or cut away, as shown in Fig. 7 and indicated by dottedlines in Fig. 8, through which projects the crankarm 0 from a hub, 7c.The other crank-arm, as 1', projects from a hub, 75", held in place bythe slotted box I.

D is a tubular stem with asomewhat tapered or squared end, which fitsdown through the bushing into a seat formed in the hub It" of the crank.The tapered portion of the stem being squared, and the seat in the hub Lbeing of corresponding shape, the crank will be turned by a rotarymovement of the stem. To the upper end of stem D is secured ahand-wheel, D.

IVhen the stem is inserted into the bushing, it is supported firmly in avertical position by an arm, (5, hinged to the dasher or hand-rail andsecured by a suitable screw or clamp, f, to an arm, f, extending atright angles from the stem D.

The end of arm f is provided with a springcatch, g, which is adapted toenter notches cut in the periphery of the hand-wheel D with sufficienteffect to retain the wheel in position against any tendency to shiftimparted to it by the jolting of the car. The notches may be placed inpositions to correspond with the different positions of theswitch-contacts which are the best for stop ping, startin g, or in otherways controlling the movements of the car.

Through the hollow center of the stem I) is passed a small round rod orstem, E, the ex-' treme lower end of which is squared and enters a seatof corresponding shape in the hub k" of crank i so that the said crankis turned independently of the others.

J To the cranks 1", or to the movable parts of the speed-switchescontrolled thereby, are connected springs w 10, which are distended whenthe speed switch is turned. These springs serve to automatically shiftthe speed switches back to their normal position when released. Theobject of this will he hereinafter more fully described.

As above stated, the main switch is operatcd and controlled by themanipulation of the hand-wheel D, which moves the crank 0, 'while eitherone of the speed-switches is independently controlled by themanipulation of the small wheel I), which is secured to the stem E, andwhich turnsone of the cranks 1', according to the end of the car towhich the hand-wheels are applied.

The function of what I term the main switch in my apparatus or system isto make or break the circuit between the generator and the motor, or tomodify the current in a proper manner to secure as far as practicablethe desired variations in power and speed of the motor. For example, themain switch might be caused to vary the resistance between the generatorand the motor, or to vary the number of battery-cells in circuit withthe motor, or in other ways to modify the character and eli'ect of thecurrent upon the motor. I prefer, however, to use a switch which isconstructed in such manner as to vary the order of the connection of thebattery-cells rather than their number, or, in other words, which in itsmovement will be capable of gradually changing the order of theconnections of the cells wit-h the motor from multiple arc to multipleseries and series and conversely. These features, while not forming,broadly, a part of my invention, are illustrated and described in detailin order that the system as a whole maybe better understood.

I may construct the switches proper in a great many different ways, theprecise mechanical construction of the same being largely immaterial,the essential features being the relative arrangement or disposition ofthe contacts which will produce the desired combination of connectionsby the movement of one part or element of the switch with refcrence tothe other. In illustration of the system or plan of electricalconnections I have shown a switch involving a set of stationary contactsand a sliding carrier to which the otherterminals are secured and whichare'reciprocated by the crank and connecting-rods above described.

Referring, therefore, to Figs. 3 and i, H is a box or case, the upperside being removed in Fig. 3, to which the stationary contacts orterminals are secured, and II is the carrier which runs on the guidesII. This constitutes the main or current-controlling switch.

In Figs. 5and (S, which represent the speedswitch, (1 is the box orcasing containing the stationary contacts, and E is the carrier or slidewith the movable contacts.

Referring now to Fig. 10, and leaving out that the carrier is shown inthis positionthat tion, or when the motor is stationary, would ofpresent consideration the connections with the speed-switches, thediagram shows the main-switch connections with the carrier H shifted toa position in which the contactstrips are out of engagement entirelywith all the stationary contacts. It may be stated is to say, on thedotted line Z lin order to illustrate more clearly the plan ofelectrical connections; but in practice its normal posibe on the line Zl. \Vhen in such position, no current will flow through the armature ofthe motor, the electrical condition being illusl trated by the diagramFig. 11, in which A designates the armature and L the field of i themotor. The speed-switch, although illustrated in this figure and inFigs. 12, 13, and 1%, may for the present be disregarded. The reason forthis will appear from the following description of connections:

The numbers 2, 7 9, 11,and 13 indicate five contact-plates, to which areconnected in series four groups or trays of the main batteries.

tray contains ten cells in series. Plates 2 and 13 therefore form theterminals of a series 1 of forty cells. In like manner forty cells areconnected in groups of ten to the contactl plates 19, 21, 22, 23, and2t. Numbers 3, 8, T and 10 designate other contact-plates between Ywhich two groups of ten cells are connected, and 12 and 14 platesbetween which is a single group of ten cells, while a similar group often cells is connected up between plate 12 and one of the brushes, as K,011 the carrier. There are, therefore, in all, one hundred and twentycells divided into twelve groups of ten cells each. The carrier ll isprovided with brushes I I l" J J J K L M, the brush J being shown in aposition in advance of the others, for reasons that will appear. .Yhen,therefore, the carrier is shifted to bring the bearingsurfaces ot' themain line of brushes in the position indicated by the line Z Z", thebrush J will rest upon plate 2, J upon plate 3, K upon plate l, and Land 31 upon plate 5; but brushes J, J, and J are electrically conlnected together and to one terminal of the motor by means of conductorm,while the ep- 3 posite terminal of the motor is, by means of theconductor 721, connected with the plates 2 and 5, and, through thebrushes L and M, resting upon plate 5, and the conductors m and m,withthe plates 3 and 19, respectively. Thus, both terminals of t 1e motorbeing in 5 electrical connection with but one pole orterminal of thebatteries, no current flows and l no action results. To start the motorin action, the carrier H is moved forward to bring the brushes therei onsuccessively in contact with the plates. i The first effect produced bythis forward movement is to establish contact between thefollowing-named parts: brush J and plate 7, brush J and plate 8, brush Jand plate 21, l

5 brought into action upon the motor.

dition of the ten cells between plates 0 and 11 j and those between 22and 23 is effected in the g 17, and conductor 0 to plate 13.

through com brushes K and L and M remaining upon the strips 4 and 5,respectively. It is evident that by this means the groups of cellsbetween plates 2 and 7, between 3 and S, and between 19 and 21 will beintroduced in parallel or multiple are into the motor-circuit, since allthe other connections remain as in the lirstdescribed position of thecarrier. The further movement of the carrier forward, which bringsbrushes J J J upon plates a, 10, and 22, respectively, obviously adds ina similar manner to each branch of the circuit acting upon the motor onegroup of ten cells of battery. hen the brushes J, J, and J haveencountered plates 11, 1;, and 23. respectively,

three groups of thirty cells each have been The adsame manner as before,while the group ol cells between plates 10 and 12 is brought intocircuit with those between plates 3 and and S and 10 by means of theconductor n from l the said group of cells to the brush K and Forconvenience, assume that each group or l plate l, and thence by acoinluctor, a, permanently connecting plates t and 10. The next changeis effected when brushes J J J encounter the plates 13, ll, and 21 orreach i each. This condition is illustrated in Fig. 12.

The next change takes place when, by the further progressive movement ofthe carrier H, the brushes K and l. have encountered the two plates 16and 17, respectively. In the interval of this passage of these brushesfrom plates l and 5 to plates lo and 17 the brush J passes beyond plateit on to insulation, while brushes J and J remain in con tact withplates 13 and it, which are made of sufficient width to permit suchmovement without interruptin the connections.

twill be noted that plate 1 3 is permanently.

, connected to plate 17 by conductor 0, and that plate it is similarlyconnected by conductor 0 to plate 16; hence this movement has producedthe following changes: Plate 3, which while brush L rested upon plate 5was connected to the motor-circuit in parallel with plates and 19, isnow thrown out of action and connected by conductor a, brush 1., platefilorcovcr, the group of cells connected, respectively, to

, the brush K and plate 12, which while brush 3 K remained on plate 4:was connected through the conductor a to plate 10, is now connectedluctor 21 brush K, plate 16, and conductor 0 to plate 2st. At thismoment, therefore, but two series of forty cells each will be connectedin multiple arc with the motor.

When the brushes J and J have encountered plates 15 and 25,respectively, from the conditions just described it is evident that onegroup of ten cells will be added to each of the two series of fortycells already in circuit.

If the carrier be then shifted to bring brushes J and J into contactwith plates 18 and 26, respectively, or on line (I q, one of theremaining groups of ten cells will be added to each of the series offifty cells in action. This occurs by reason of the fact that plates 15and 18, by means of com'luctors p p, are respect ively connected toplates 8 and 10, between which one of the groups of cells is included,and plates and 2t; similarly connected by conductors r r to plates 12and 14, between which the other group of cells is included. All of thecells will thus be brought into action in two series of sixty cellseach, as represented'in Fig. 13. The next change is effected by thefurther 1.)rogressive movement of the carrier H, which transfers thebrush M from plate 5 to plate 20. By this movement plate 19, which solong as brush M remain ed on plate 5 was connected to the motor--circuit, first in multiple arc with plates 2 and 3 and next with plate2 alone, is connected by conductor m, brush ill, plate 20, conductor g",plate 4, conductor 12', plate 10, and

conductor with plate 18; but at the same time brush J passes onto plate19, while brush J passes from plate 26 on to insulation. One series ofsixty cells, or those now included between plates 2 and 19, willtherefore remain in action, while the other cells are connectedin seriesbetween plates 19 and so, but are out of action.

It will be noted that strips 19, 9],

24, and 26 are of double width, so that they.

ously adds the group of ten cells included be tween plates 19 and 21 tothe series of sixty cells already in action, and the further move mentof the carrier in like manner adds ten additional cells to the series inaction for each successive plate encountered by the brushes J J untilsaid brushes reach the final plate, 26, when all of the one hundred andtwenty cells are connected in series with the motor, as shown in Fig.14. While with this arrange ment the switclrcarrier may be shifted toany intermediate position, it is desirable, in order that all the cellsmay be equally drawn upon, that the brushes be maintained at one oranother of the positions indicated by the lines Z Z, &c., and at whichthe corresponding electrical connections will be as shown in Figs. 11 toll, inclusive.

011 the carrier H are supported two supplemental brushes, I and I, whichare designed to maintain the motor-circuit constantly closed during theshifting of the main brushes from strip to strip. This is accombrushes JJ, &c., are made as wide as they may safely be without actually spanningand short-c-ircuiting adjacent plates in passing across the interveninginsulation or space.

The letters .9 s indicate the resistance-circuit-s between the brushes II" and the branched conductor 5-, which establishes connections to eachof the brushes J J J. In illustration of the action of the supplementalbrushes, assume the carrier to be in position to maintain the mainbrushes on plates 7, S, and 21. and to be then shifted to bring thebrushes onto the next set of plates. The relative lengths of the mainand supplemental brushes are such that j ust before brush J breakscontact with plate 7 brush I comes into contact with plate 9, and themoment after brush J reaches plate 9 the brush I breaks contact withplate 7. The special advantage of using the two supplemental brushesresides in the opportunity which they afford of utilizing bothresistances s s, for itwill be observed that at every passage of themain brushes from strip to strip a group of cells is momentarilyshort-circuited through the supplemental brushes and the two resistancess s in series, but that the current to the motor from the cells alreadyin circuit has only one-half of the resistance to overcome. There isalso 011 the carrier H a brush, I, electrically connected to the mainbrushes. This brush has a special function in connection with what Idesignate the speed-switch, which will be understood by reference toFig. 15, in which the brushes are advanced to the position correspondingto the line 13"]3 in Fig. 10. In this figure IT and N represent metalliccontact-levers, on one side of which are two plates, 28 and 29, and onthe other a given number of plates, as 30, ill, 32, 33, and 34, adaptedto be successiy'ely brought into contact with the lever N or N by themovement of the said lever. The normal position of the levers is, asshown, on both plates 28 an d 29.

From brush I electrical connection is maintained to one terminal of themotor field-coil, through conductors s" and m. In the path tion betweenthe plates 28 and 2.).

surfaces when the brushI is shifted out of contact with plate 6.

Between plate 6 and the opposite terminal of the motor field-coil agroup of cells, 0, is included, the electrical connections beingmaintained by means of conductors I37, 38, and 39, plates 28 and 20, andthe switch-levers N and N. These supplemental cells thus maintainedunder normal conditions in circuit with the field when the motor is inac tion tend to impart to the field the same polarity as the mainbattery.

Around the field-coils I] of the motor is a series of resistances, It),ll, l2, and 43, to be used for shunting more or less of theenergizing-current around the field. In the present instance, where twoswitches atopposite ends of the car are shown for controlling theseresistances, the conductor H connects one side of the field-circuit withboth plates 30. The remaining plates, 31, 32, 33, and 3t, are 0011-neoted across by conductors I5, 41;, t7, and 4:8, repectively.Resistances 41,42, and t3 are includedbetween the conductors l5 to 48,as shown, and resistance It) is between the opposite side of thefield-circuit and conductor 41.

Normally, as above stated, the position of the levers N maintainselectrical connec- The first effect of shifting the carrier to start themotor is to bring the supplemental cells 0 into action upon themotor-field. This condition of things remains unaffected by the furtherma nipulation of the main switch until the brush I is shifted to eitherof its extreme positions. If, however, it becomes desirable at-any timeto increase the speed of the motor beyond the rate determined by anygiven position of the main switch, one of the levers, N or N, is shiftedout of contact-with plates 28 and 99 onto two or more of the otherplates of the speedswitch. This is effected, as hereinbefore set forth,by turning the small handwheel D. The first result of this shiftingis toopen the circuit of the supplemental cells 0, while the further movementof the lever by connecting plate 30 successively with the plates 31 to234C shunts the currel'lt around the field of the motor, reducing thestrength of the field and producing in consequence an increase in thespeed of rotation of the armature. This effect, as is well known, is dueto lowering the counter clectro-motive force of the motor armature byweakenin the strength of the field in which it rotates. The rate ofspeed is obviously controlled by the number of resistances cut out bythe speed-switch.

The main advantages in the use of this supplemental or speed switch inconjunction with the main switch are as follows: First, it is desirable,as I have before stated, to utilize by some order of connections all thebattery-cells simultaneously in order that they may be equally drawnupon; but as the 'number of possible combinations of all the cells islimited, and also involves considerable complication in the switchmechanism, by the use of the speed-switch, which varies the counterelectro-motive effect of the motor without varying the number orarrangement of cells, all intermediate speeds may be obtained; secondly,the motor is geared to the driving axle or axles of the car, so that thenormal rate of speed will be secured by the most economical speed of themotor for the battery-power used; but it is often desirable to make uplost time or to run at a higher speed for some other reason, in whichcase the speed-switch is advantageously used, although the motor may notbe actually running under the most economical conditions.

The main object of the use of the supplemental cells 0 is to enable theenergy to be stored which would otherwise be expended in stopping thecar or wasted by the running of the car down a grade. In illustration ofthis, suppose the car while running at its normal speed is to bestopped. The main switch is shifted to reduce the number of cells inseries acting upon the motor. If the field of the motor were permanentlymagnetized, it is evident that as soon as the electro-motive force ofthe battery fell below that produced by the motor at its normal speedthe motor would act as a generator and charge the cells; but in mysystem, where I employ a series-wound machine, a reduction of theelectro-motive force of the battery is followed by a reduction in theintensity of the field. In order, therefore, to prevent the magnetism ofthe field from being reduced to zero by the lowering of theelectro-motive force of the battery and the tendency of the motor whenrunning to reverse its own field, I employ the supplemental battery 0,which imparts to the field of the motor sufficient magnetism to cause itto run as a generator and charge the battery when either theelectro-motive force of the battery is slightly reduced or the speed ofthe motor accelerated by the motion of the car downgrade. This evidentlyacts as a b ake, either to stop the car or to prevent its too rapidmotion on a downgrade. The number of supplemental cells used in this waywill depend upon the resistance of the field-circuit and the currentstrength normally used in running the motor. I have found in practicethat good results are obtained by the use of three supplemental eellswith a motor, the resistance of the fieldcircuit of which was aboutthree-tenths of an ohm, and which wasoperated by one hundred and twentycells similar to the supplemental cells; but I have reason to think thatthe number and arrangement of the supplemental cells which will yieldthe best results in particular cases are most easily determined byexperiment. These cells do not require recharging as frequently as themain-battery cells, for the reason that they will be found at times toreceive charge from the main battery. The use of these supplementalcells enables me to use a series wound motor, which is preferable incases of this kind, for the reason mainly that it starts far betterunder a load than the shunt-wound type of motor. The addition of thesupplemental cells, moreover, enables me to stop the car as readily aswith a shuntwound motor and to charge back into the batteries, or incase the battery be stationary and the current conveyed to the motor tocharge back to line.

The electrical conditions of the speed-switch with reference to the mainswitch at the various positions of the latter will now be understood byreference to Figs. 11 to 14. In Fig. 11 the supplementalbatteryisinelinled in the field-circuit through the resistance 35, brushI being in contact with plate 1. In Figs. 12 and 13 the battery 0 isdirectly in circuit with the field, while in Fig. 14, which representsthe conditions in which brush 1 rests upon plate 27, the resistance 30is brought into circuit with the battery 0. This reduces somewhat themagnetic strength of the field and enables the motor to run at aslightly-greater speed than it otherwise would.

In practice the speed-switch, as I have now described it, performs auseful function in the operation of stopping the car. The movable pa-rtof the switch is retracted, as above set forth, by spring 10, so thatwhen turned and then released it will suddenly shift back to its normalposition. This property I take advantage of in the following manner: Tostop the car, the guard turns both switches together until the point isreached where the motor should charge back into the battery. The speedswitch is then released, and, returning to its normal position, throwsthe supplemental cells into the motor field-circuit. As the firstmovement of the speed-switch cuts out the supplemental cells from thefield-circuit, it will be seen that the current of both the main andsupplemental batteries is withdrawn from the motor, so that there willbe no injurious sparking at thcmain switch; but as soon as theeleetro-motive force of the battery is reduced by changin the order ofthe connection of its cells from series to multiple arc to a point atwhich the motor, propelled by the momentum of the car, would charge backinto the battery it it were not inert by the withdrawal of energizingcurrents the speed switch is released, and, being automaticallyretracted, it throws in t-he'tield-cells again.

Referring now to Fig. 9, all the essential details being designated bysimilar letters and characters to the corresponding parts in the otherfigures, the diagram will be readily understood. It may be stated thatthe bar 6 of the speed-switch carries two contact-plates, X Y, insulatedfrom each other. The plates 28 and 29 are connected by the plate X, andplate 30 is connected with one or more of the plates 31, 32, 33, and Siby the contact-plate Y.

It will also be observed that in Fig. 9 four long plates are shown inthe switch'and dcignated 49, 50, 5], and 52. Theyser've merely tomaintain the same electrical connections that are made through theconductors m, m", n, and 'n of Figs. 10 and 15, to which theyrespectively correspond. In the two figures named these conductors areassumed to include flexible portions, as indicated, which maintain theconnections with the movable brushes. In Fig. .0 these parts arereplaced by the long strips.

In Figs. 3 and 15 is shown an auxiliary appliance which serves as asafety device.

To prevent the person in control of the car from permitting an excess ofcurrent to be drawn from the batteries, as might occur by turning themain switch too rapidly in starting or in increasing the speed of thecar, I employ a magnet, F, with an adjustable armature, F. This magnetis included in a circuit, 55, between the plate 2 and one terminal ofthe motor. When any current is flowing from the main batteries to themotor, either from all the coils in series or from the two or threegroups in multiple are, the magnet F will be energized. Its armature isso adjusted that it will not be moved by any current at or below thenormal; but should the current strength exceed the normal limit it willbe caused to engage with one of the notches r inthe switch-bar B andprevent the further movement of said bar until. the counterelectro-motive force of the motor has risen sufficiently to reduce thecurrent to the normal. I also use with the magnet a local circuit, T,containing a bell, T, and which is closed by the movement of thearmature F toward the magnet. This gives intimation to the guard orattendant when the current is too strong. I employ this device in placeof the current indicators or ammeters commonly used.

The practical importance of this system or combination of appliancesdevised by me depends largely upon the employment of the series-woundmotor with the storage-battery and the means by which its regulation andcontrol are eftected. No means, so far as I am aware, have 'heretoforebeen devised for causing such a motor to charge back into the batterywhen the car is stopping or running without the battery-curreiit.

I do not claim herein, broadly, the combination of a main and a speedswitchthat is to say, of a switch that varies and controls the currentsupplied to the motor and a switch that varies the intensity ot themagnetic field of the motor; nor do I broadly claim in this applicationthe method of operating these switches which I have herein described.

lVhat I desire to secure by Letters Patent 1s 1. The combination, in anelectro-magnetically-propelled car, with a series-wound motor and a mainbattery or source of current for driving the same, of a supplementalbat= tcry and switch for connecting the same with the field-circuit ofthe motor, as set forth.

2. The combination, in an electromagnetic ally-propelled vehicle, of aseries-wound mo tor, a main battery for supplying the current to run themotor, a main switch for controlling and varying the current supplied bythe battery, a speed-switch adapted to vary the strength of thefield-magnets of the motor, and a supplemental battery adapted to beconnected with and disconnected from the field coils of the motor by theswitches, as herein set forth.

The combination, with the motor, of a main and speed switch havingrotary handles or devices for manipulating the same mountedconcentrically, as set forth.

at. The combination, with a car or other vehicle and a drivingelectro-magnetic motor mounted thereon, of manual switches adapted,respectively, to vary and control the current supplied to the motor andto vary the magnetic intensity of the field of the motor, the latter orspeed switch being automatically retractile to its normal position, asherein set forth.

5. The combination,with the main contactbrushes mounted in aninsulating-carrier and the series of battery-terminal plates in positionto be successively encountered by the said brushes, of independentsupplemental brushes adapted to maintain contact between two adjacentplates during the interval of the passage of the main brushes from oneto the other, and resistance-circuits connecting said supplementalplates to the main plates, as herein described.

o. The combination, with the series-wound motor of anelectrically-propelled car, of a battery of a comparatively small numberof cells normally included in the field-circuit only of the motor whilethe car is running and acting to impart to the field the same magnetismas the main battery, and for the purpose set forth.

7. The combination, with the main contactbrushes mounted in aninsulating-carrier and the series of battery-terminal plates in positionto be successively encountered by the I said brushes, of independentsupplemental brushes adapted to maintain contact between two adjacentplates during the interval of the passage of the main brushes from oneto the other, and resistance-circuits connecting said supplementalplates to the main plates, as herein described.

8. The combination, with the series-wound Q motor of a car, of asupplemental battery in the field-circuit and a resistance adapted to beinserted in the circuit with said. battery, as and for the purpose setforth.

9. The combination of the series-wound motor, the main switchcontrolling the current to the motor, the speed-switch for yarying themagnetic couple of the motor, and the supplemental battery in a circuitincluding the iield-coils of the motor and adapted to be controlled bythe main and speed switches, as and for the purpose set forth.

10. In an electromagnetically-propelled vehicle, the combination of asecondary or storage battery, a series-wound electro-magnetic motor, andswitch mechanism for directing a current independent of the main ordriving current through the field-circuit only of the motor in the samedirection as the main current, as and for the purpose set forth.

11. The combination, with a car or other vehicle and a series woundelectric motor mounted thereon, of a secondary or storage batterycarried by the car, a switch for varying and controlling the currentsupplied to run the motor, and means for maintaining the normalmagnetism of the motor field when the batterycurrent is'interrupted orreduced, whereby the motor may be caused to charge back into the batterywhen the electro-motive force produced by the battery has fallen to agiven point, as set forth.

\ILLIAM L. STEYEXS.

Witnesses:

FRANK G. PARKER, MATTHEW M. BLUNT.

